The present invention relates generally to fusion bonding, and more particularly to the alloy bonding of indium bumps to gold pads and methods of forming same which produce bonded bump and pad structure that are suitable for use in integrated circuits and their processing, and the like.
Prior art bump and pad arrangements have been around since the 1960's. These include the well-known solder to solder bump contact developed by IBM, the indium to indium bump contact developed by the Santa Barbara Research Center, a subsidiary of Hughes Aircraft Company, and the gold to gold bump contact developed by Honeywell. Each of these contacts is processed by means of a reflow procedure, and the bump and pad structures may be welded together in any conventional welding manner.